Tailoring Built‐in Electric Field in a Self‐Assembled Zeolitic Imidazolate Framework/MXene Nanocomposites for Microwave Absorption

Abstract The use of heterointerface engineering, which can play a pivotal role in producing advanced microwave‐absorbing materials, to prepare a zeolitic imidazolate framework (ZIF)–MXene nanocomposite is reported herein. The ZIF–MXene composites can be prepared by electrostatic self‐assembly of negatively charged titanium carbide MXene flakes and positively charged Co‐containing ZIF nanomaterials. This approach effectively creates abundant Mott–Schottky heterointerfaces exhibiting a robust built‐in electric field (BIEF) effect, as evidenced by experimental and theoretical analyses, leading to a notable attenuation of electromagnetic energy. Systematic manipulation of the BIEF‐exhibiting heterointerface, achieved through topological modulation of the ZIF, proficiently alters charge separation, facilitates electron migration, and ultimately enhances polarization relaxation loss, resulting in exceptional electromagnetic wave absorption performance (reflection loss RL min = −47.35 dB and effective absorption bandwidth f E = 6.32 GHz). The present study demonstrates an innovative model system for elucidating the interfacial polarization mechanisms and pioneers a novel approach to developing functional materials with electromagnetic characteristics through spatial charge engineering. This article is protected by copyright. All rights reserved